When Is an f/2.8 Zoom Worth the Extra Weight?

An f/2.8 zoom usually costs more, weighs more, and takes up more room in your bag than its f/4 counterpart, and the price gap between the two versions of the same focal range can run to hundreds of dollars. A wrong choice in either direction tends to end the same way, with a second purchase or an expensive lens that keeps getting left at home. [Read More]